Loop-taker-actuating mechanism for sewing-machines



P. A. HERR.

LOOP TAKER ACTUATING MECHANlSM FOR SEWING MACHINES.

APPLICATION FILED SEPT- 30; 1919.

1 2. 9 1 V Lu N M 4 m a P IIVENTO'R h 4. JW BY P. A. HERB.

ILOOP TAKER ACTUATING MECHANISM FOR SEWING MACHINES.

APPLICATION FILED SEPT. 30. I919.

1,396, 040 Patented Nov. 8 21..

4 SHEETS-SH I III/III V I I T IIIIIIIIIIVI, A I

WITN SSES' INVENTOR BY wf P. A. HERR.

LOOP TAKER ACTUATING MECHANiSM F0 R SEWING MACHINES.

APPLlCATION FILED SEPT. 30. 1919.

4 SHEETS-SHEET 3.

Patented Nov. 8, 1921.

P. A. HERB.

LOOP TAKER ACTUATING MECHANISM FOR SEWING MACHINES.

APPLICATION FILED SEPT. 30, 1919.

Patented Nov. 8, 1921.

4 SHEETS-SHEEY 4.

ATTORNEY UNITED STATES PATENT OFFICE.

PARK A. HERE, 0]? HILLSIDE, NEW JERSEY, ASSIGNOR 'lO THE SINGER MANUFAC- TUBING COMPANY, A CORPORATION OF NEW JERSEY.

LOOP-TAKER-ACTUATING MECHANISM FOR SEWING-MACHINES.

Application filed September 30, 1919.

To all whom it may concern:

Be it known that I, PARK A. HERR, a citizen of the United States, residin at Hillside, in the county of Union and tate of New Jersey, have invented certain new and useful Improvements in Loop-Taken Actuating Mechanisms for Sewing-Machines, of which the following is a specifi catlon, reference being had therein to the accompanying drawings.

This invention relates to sewing machines of the type employing oscillating looptakers and more particularly to the mechanism for imparting to the loop-taker its oscillatory movements.

The invention has for an object to increase the speed of the machine by reducing the extent of oscillation of the shuttle or other loop-taking element. and still retain the proper timing of the respective parts.

A further object of the invention is to provide a looptaker actuating mechanism adapted to impart a variable motion to the loop-taker shaft whereby the loop-taker is given a retarded motion or dwell at a certain stage of its oscillation permitting the needle-eye to rise above the work before substantial distention of the needle-thread loop begins, thereby greatly reducing the frictionon the. thread during such distention.

According to the present invention the objects are attained in a shuttle-actuating mechanism comprising a main-shaft provided with a crank to which is connected one end of a two-part pitman comprising a short upper section and a comparatively long lower section. This pitman is reciprocated by said crank and is at its lower end suitably connected to oscillate the looptaker shaft. The upper orshort section of the pitman is pivoted to turn about an axis located comparatively near the main-- shaft and, due to the relation of the arcs in which the crank and the upper section of the pitman move, the reciprocatory motion of the pitman is retarded and accelerated at different stages, thereby correspondingly affecting the movements ofthe shuttle, as will later by explained.

By the employment of the present mechanism it becomes possible to use a short-beak shuttle or other loop-taker and to still allow the needle-eye to rise above the work before substantial distention loop begins.

Specification of Letters Patent.

of the needle-thread Serial No. 327,377.

Heretofore, in order to obtain this conditioinit has been customary to employ a shuttle having a beak substantially longer than is used with the present mechanism, which necessitated correspondingly greater oscillation of the shuttle to position the point thereof in rear of the needle preparatory to taking the thread-loop, and by eliminating this excessive oscillation it is practicable to run the machine at a substantially increased speed.

The invention is shown in its preferred form in the accompanying drawings, in which Figure l'is a side view partly in section of a sewing machine embodying the present invention. Fig. 2 is a front end elevation thereof. Fig. 3 is a sectional view taken on the line 33 of Fig. 1. Fig. 4 is detail bottom view howing the mechanism for converting the reciprocatory motion of the pitman into oscillatory motion of the loop-taker driving shaft and Figs. 5,

v6 and 7 are detail views, in different posiminating in the head 4. Journaled within the arm 3.is a main or needle-bar driving shaft 5 carrying at its rear end a beltand hand-wheel 6 and having secured at its front end a disk 7 which carries a crankpin 8 connected by a link 9 to a block 10 secured upon the' needle-bar 11, whereby reciprocatory motion is given to the needlebar and to the needle 12 secured therein and which carries the needle-thread t. A springdepressed presser-bar 13 is shdingly mounted in the head 4 and carries at its lower end the presser-foot 14. A throatplate p, adapted-to support the work w being acted upon, is located beneath the presser-foot and is supported'by the machine base.

Thread take-up mechanism 15 is also car- ,ried by the head 4 and actuated from the formed with a loop-seizing beak 18 and sup-' porting the bobbin-case 19 adapted to carry the bobbin 20 upon which is wound the bob- Patented Nov. 8, 1921.

' prising a single element, have been pivoted.

It will be understoodthat the. more nearly 7 'otally connected to a lower or longer section 28 by a screw 29. In the present embodiment of the improvement the lengths of the sections 27 and 28 are about as one-to-four and-the section 27 isabout two-and-one-half times the length of the "actuating crank to which it is directly connected. The pitman d has, at. its upper end, a strap embracing the crank 26 and at its lower end is pivotally connected to a motion-converting and multiplyingmechanism comprising a crankor rock-arm 30 fixed upon the short-rock-shaft 31 journaled in bearings 32 carried by the machine base 1 and a second rock-arm 33 whichis connected by a link 34 to a crankor rock-arm 35 carried'by the rear end of" the loop-taker shaft 24:. r

A radius-arm 36, adaptedtocontrol the path of movement of the pitman is connected at one end to the pivot-screw 29 and has its other end fulcrumed upon a bracket 37 forming a partof the machine standard.

Referringto Fig. 6, it will be observed that, as. the short section of the pitman is pivoted'to turn about anaxis. located comparatively near the main-shaft, an are a, swung from said axis, approximates the are I; in which the crank turns when approach ing and leaving its uppermost position.

The are a is swung from a point .23 disposed eccentrically to the rock-shaft. 31 -where drivingconnections, as heretofore used, com

an arc swung from the pivot point of the upper section'of .the pitman approximates the path of movement of the crank the lesser will be the. reciprocatory movement of said pitman, and consequently the; shuttle movement,at that time, will'be retarded.

As the crank is passing itsj'lowermost position itturns in anarc f oppositely disposed to an arce swung from the axis of the short 7 pitmlan-sectio'n, which at that time is in its lowermost position as is also. the radius-arm 36 of which the centerline is represented by the dot-dash line 36*,causing anincreased endwise movement of the pitmanand a coreresponding acceleration of theshuttlemovement, equal in amount to its previous retard ation, thereby keeping. the several partsin propertime for the formation of the succeeding stitch. In'one aspectof the present. improvement, the .link element 28 is con-' nected, g1 not" directlywith' its actuating ,ele;

1. Ina sewing machine, the'combination with" an overhanging arm, a driving shaft supported thereby, a crank carried by said shaft, an oscillating shaft, and stitch-forming-mechanism comprising a needle and a loop-taper adapted to take a loop of thread from 'thenee dle and .distend' the loop, of means connected withthe said oscillating shaft for actuating said loop-taker whereby the movement thereof is retarded at a predetermined time to permit the needle to rise 5 above the work before substantial distention oftlie loop begins, said means includ ing a two-part pitman composed of pivotally connected sections of which'one is con nected to .the crank on the main-shaft and the otherto a motion converting mechanism linked to an arm carried by saidoscillating shaft;

,2. A loop-taker actuating mechanism for sewing machines comprising a main-shaft, a crank carriedthereby, a loop-taker shaft; provided witha rock-arm, a rock-shaft, a

rock-arm carried thereby, a link connect-1 ing said rockarms, and a pitman, comprisg ing sections pivotally connected together, and connected to said crank and controlled to actuatesaid rock-shaft.

3. A'loop-taker actuating mechanism for sewing machines comprising a main-shaft, a crank carried'thereby, a loop-taker shaft provided with a rock-arm, a rock-shaft, a

rock-armcarried thereby,. a link 3 connecting saidrock-arms, and a two-part pitman controlled to actuate said rock-shaft and comprising relatively short and long sec-v tions pivotally connected together and con-. nected respectively to the crank andto an arm on the rock-shaft;

4.A loop-taker actuating mechanism for sewing machines comprising a mainshaft, a crank thereon, a loop-taker shaft provided witha. r0ckarm, a rock-shaft, a rock-armthereon, a'linkconnecting said rock-arms,

and a two-part pitman controlled to actuate said rock-shaft and comprising a relatively short section connected to said crank and a relative long section pivotediat one. end to said short section and eccentrically' count-feted at its other end to said rock-shaft."

A loop-taker actuating mechanism'for sewing machines comprising a mainshaft, a crank thereon, a loop-taker shaft provided with a rock-arm, a rock-shaft, a rock-arm carried thereby, a link connecting said rockarms, a pitman, comprising two pivotally connected sections, of which one is connected to said crank and the other is connected to said rock-shaft, and means for controlling the direction of movement of the component sections of said pitman.

6. A loop-taker actuating mechanism comprising a main-shaft, a crank thereon, a rock-shaft, a crank thereon, a pitman connection between said cranks composed of two pivotally connected sections of unequal length of which the shorter is pivotally connected to the mainshaft crank and vthe longer is connected to the rock-shaft crank, and means for controlling the path of movement of the pivotal connection between the pitman sections.

7. A loop-taker actuating mechanism comprising a main-shaft, a crank thereon, a rock-shaft, a crank thereon, and a dwellproducing driving connection between said cranks and including a two-part pitman with pivotally connected component sections of different length of which the shorter is directly connected with the main-shaft crank.

8. A loop-taker actuating mechanism comprising a main-shaft, a crank carried thereby, a loop-taker shaft provided with a rockarm, a rock-shaft, a rock-arm carried thereby, a link connecting said rock-arms, a pitman comprising pivotally connected sections embracing said crank and adapted to actuate said rock-shaft, and means for controlling the movement of said pitman, said means including a radius-arm pivotally connected at one end to said pitman and fulcrumed at its other end upon a fixed support.

9. A loop-taker actuating mechanism for sewing machines, comprising a main-shaft, a crank thereon, a loop-taker shaft provided with a rock-arm, a rock-shaft, a rock-arm carried thereby, a link connecting said rockarms, and a pitman composed of a plurality of pivoted sections connected at one end to the crank on the main-shaft and eccentrically connected at its opposite end to the rock-shaft, whereby one end of one of said sections'is moved in a circular path defined by said crank and the other end acting through another of said sections transmits variable oscillatory motions to the shuttleshaft.

10. A loop-taker actuating mechanism for sewing machines, comprising a rotary shaft provided with a loop-taker actuating element, a loop-taker driving shaft, a looptaker operatively connected therewith, a pitman element connected with and imparting operative movements to said loop-taker driving shaft, and a driving connection includ ing a motion-retarding device between said pitman element and said loop-taker actuating element.

In testimony whereof, I have signed my name to this specification.

PARK A. HERR. 

